1. Field of the Invention
The present invention relates, in general, to high pressure snap fit or quick connectors employed on fluid conduit systems and, more particularly, high pressure quick connectors employed on vehicle brake lines.
2. Description of the Art
Snap fit or quick connectors have been found to be useful in a wide range of applications. In particular, they are frequently employed for joining fluid carrying conduits in automotive and industrial applications. Such connectors have found general acceptance as they are typically capable of being closed in a single uni-axial movement which facilitates automated assembly, and entail simple designs which are relatively inexpensive to produce.
A further advantage of quick connect fittings is that they provide an effective seal for handling volatile or hazardous fluids, such as gasoline, while permitting ease of disassembly and reassembly during repair of a host system.
In applications where hazardous material is to flow through a fitting, for example, in vehicle brake lines, prevention of inadvertent release of the quick connector is of primary concern. Accordingly, relatively high axial pull apart strength specifications are mandated. In addition, low insertion forces are required.
Currently, for many high pressure applications, such as with brake lines, threaded fittings are used as connection means. If not aligned correctly, cross threading may result. If excessive torque is applied, over threading may result. As a result of cross-threading or overthreading, the threads are stripped and the material must be scrapped and replaced.
In current anti-lock brake systems, the brake lines are connected to a brake manifold or junction during the assembly process of the vehicle. The threaded connections of the prior art are located close together which increases assembly time and labor as well as the potential for error.
A further disadvantage typical of prior art high pressure quick connectors is that they must be assembled with an associated tube and shipped to a final destination as a single assembly. Such shipment is expensive and subjects the connectors to damage from mishandling.
Further, such quick connector designs frequently require the presence of a resilient seal between the outer peripheral surface of the tube and a mating bore which can result in leakage. This is a particular problem with multi-layer, high pressure steel tube typically used in automotive brake lines. Finally, it is difficult to perform in-process leak checks prior to final installation and very expensive to correct leaks after final installation.
One attempt by the present Assignee to alleviate these shortcomings is shown in U.S. Pat. No. 5,711,549. This high pressure quick connector is in the form of a housing, and a tube retainer with a lower cylindrical portion sealingly engaging a flared end form of a tube. A pop top and snap ring are inserted into a bore in the housing until the pop top contacts the end of the housing. This causes the top to slide up and out and releases the snap ring ears into a groove in the housing to lock the snap ring, the retainer and the tube in the housing.
While this type of quick connector meets the requirements of providing a high pull out force and low insertion force, there still exists difficulties in achieving reliable insertion of the snap ring into the grooves and the housing.
Therefore, it is desirable of the invention to provide a quick connect for high pressure automotive system applications an particularly for brake systems which facilitate assembly of the quick connect so that it is easier and quicker. It is also desirable to provide a quick connector for high pressure fluids that provides high axial pull apart strength and low insertion force specifications. It is further desirable to provide a connector that eliminates the threaded connection to reduce scrap as a result of cross-threading. It is also desirable to provide a quick connector for high pressure fluids that has improved reliability in securely inserting the retainer in the housing.
The present invention is a quick connector which overcomes many of the shortcomings of previously devised quick connectors by providing easy and reliable insertion and secure mounting of a retainer into a quick connector housing.
In one embodiment, the present invention is a quick connector which includes a fluid carrying tube, a first connector having a housing with a bore extending therethrough and an annular inward facing channel spaced from one end of the housing and opening to the bore, a second connector including a spool having a bore extending therethrough for receiving a tube, and a retainer having an aperture in an end portion for receiving the tube therethrough and a plurality of legs movably extending from the end portion for latching engagement in the channel to lockingly couple the spool and tube in sealing engagement with the first connector.
Means are also provided about the tube and movable along the tube, for moving the legs between a radially inward position allowing passage of the legs into the bore in the first connector housing and a radially outward expanded position wherein ends of the legs engage the channel in the housing.
Preferably, the legs have planar ends engageable with the channel. The planar ends of the legs extend outward from side edges of the legs. The legs extend radially outward from one end portion to outer ends. The outer ends of the legs are at a nominal diameter greater than the inner diameter of the bore in the housing.
The legs may have end pads engageable with the channel. Each of the pads preferably have an arcuately shape with opposed ends circumferentially spaced from the ends of adjacent end pads.
Further, the quick connector of the present invention includes means, engageable with the retainer after the retainer has been coupled to the housing, for maintaining the legs of the retainer in radially outward engagement with the channel. The maintaining means is in the form of a clip means, insertable between the legs of the retainer and the spool, for maintaining the legs in a radially outward position with respect to the spool. The clip means is preferably a U-shaped clip having two spaced legs joined by an end wall. Each leg is insertable through two aligned openings formed between the legs of the retainer and the spool. Outwardly extending hooks are formed at the ends of each of the two spaced legs to prevent disengagement of the clip from the retainer. A stop means is formed on the legs for limiting the insertion distance of the clip into the retainer.
The quick connector of the present invention uniquely assures easy mountability and insertion reliability of mounting the retainer in the bore of a female connector. This provides an improvement in ease and reliability over previously devised male to female endform connectors. Further, the use of the unique assurance clip ensures that the retainer legs remain engaged with the channel in the housing to lock the retainer in place.